Fig. 1: Scheme showing the PPi-responsive photonic alginate hydrogel particles for alkaline phosphatase quantitative detection.
a The fabrication process of the hybrid photonic microparticles. b The detection mechanism of the hybrid photonic microparticles. When adding PPi, the hydrogel network could be disrupted due to PPi’s strong competitive coordination effect with Cu2+, resulting in the leakage of inner CDs to the external solution. This could trigger a simultaneous decrease in the fluorescence intensity and blueshift of the reflection spectrum of the particles. ALP can react with PPi and suppress the disintegration of the hydrogel to a certain extent depending on the ALP concentration. Therefore, quantitative detection of ALP could be achieved by measuring the dual optical signals.
